The present invention relates to a laser machining device, and more specifically to a laser machining device for drilling, cutting, or marking a material of a printed board, a semiconductor chip or the like such as resin or ceramics.
As a laser machining device for drilling, cutting, or marking, there has been well known the one having a structure as shown in FIG. 46.
This laser machining device has a laser oscillator 1 which is a source of a laser beam L, a collimate lens 2 for adjusting a divergence angle of the laser beam, Y-axial and X-axial galvanomirrors 3 and 4 each for deflecting the laser beam L to a required direction based on the rotation angle, a Y-axial galvanoscanner 5 and an X-axial galvanoscanner 6 each for adjusting rotation angles of the Y-axial galvanomirror 3 and X-axial galvanomirror 4 respectively according to a machining program, and a converging lens 7 for introducing and converging the laser beam L deflected by the Y-axial galvanomirror 3 and X-axial galvanomirror 4.
Wavelength of the laser beam L generated by the laser oscillator 1 varies according to a quality of a work to be machined, but in many cases a carbon oxide gas laser is used as the laser oscillator 1.
The converging lens 7 is an optical lens capable of deciding a converging position according to the incidence angle of the laser beam, and changes a converging position according to an incidence angle decided under deflection control by the Y-axial galvanomirror 3 and X-axial galvanomirror 4.
The laser machining device has an XY table device 8 for mounting and positioning of a work W to be machined, and by moving the work W can change the relative position of the work W with respect to the converging lens 7 according to movement of the XY table device 8 along the axes. Laser beam L converged by the converging lens 7 is irradiated onto the work W mounted on the XY table device 8.
Adjacent to the XY table device 8, there is provided a vision sensor 9 for detecting a machined position on the work W machined by means of irradiation of the laser beam L.
Connected to the laser machining device is a control unit 10 such as a numerical control unit for driving and controlling the laser oscillator 1, Y-axial galvanoscanner 5 and X-axial galvanoscanner 6. In many cases the control unit 10 is a PC-NC having a personal computer as a user interface, and has a machining program with machining positions or conditions for machining described therein previously stored in the personal computer.
Types of machining required in a laser machining device include drilling of a small hole having a diameter in a range from 50 xcexcm to around 200 xcexcm, and in this type of machining for drilling a small hole it is necessary to converge a laser beam onto a very small spot having a diameter in a range from 50 xcexcm to around 200 xcexcm on the work W to be machined. To achieve this, the converging lens for converging a laser beam onto a work W is used.
A light path of a laser beam outputted from the laser oscillator 1 to the work W has a certain distance, so that the laser beam diverges while propagating this light path and the diameter of the beam becomes larger on the Y-axial galvanomirror 3 and X-axial galvanomirror 4. To obtain a required diameter for the laser beam, adjustment of the divergence angle of the laser beam is required. To achieve this, the collimate lens 2 is provided in the light path to adjust the beam diameter.
To irradiate the laser beam L onto a required portion of the work W, the Y-axial galvanoscanner 5 and X-axial galvanoscanner 6 are driven to change the rotation angles of the Y-axial galvanomirror 3 and X-axial galvanomirror 4 so as to deflect the laser beam to a required position in a required direction. Coordinates on the work W are unitarily decided according to an incidence angle xcex8 of the deflected laser beam with the converging lens 7.
In response to a start instruction from an operator or a start signal inputted from the outside the control unit 10 executes machining based on the selected machining program. In this machining program, data for required machining positions are converted into the coordinates of the XY table device 8 as well as into the coordinates (rotation angles) of the galvanoscanners 3 and 4.
When executing a machining program, the control unit 10 outputs a drive signal according to the machining program so that large movement is executed by means of movement of the XY table device 8 in which many movement strokes can be set, and small movement is executed by means of scan movement of the Y-axial galvanomirror 3 and X-axial galvanomirror 4 each having a high moving speed.
Generally a DC servo motor is used for the Y-axial galvanoscanner 5 and X-axial galvanoscanner 6, and the technique for providing a position detector or servo control is often employed. Generally the XY table device 8 is driven and controlled by a servo motor using a ball screw.
The Y-axial galvanoscanner 5 and X-axial galvanoscanner 6 can make positioning at a high speed of a round 500 holes/s, and the XY table device 8 can be driven at a speed of 30 m/s. Presently, a positioning precision for the Y-axial galvanoscanner 5, X-axial galvanoscanner 6 and XY table device 8 can be achieved to a level of around xc2x120 xcexcm.
Generally the converging lens 7 is classified as a conversion lens, and is often used as a combination lens called as the fxcex8 lens. FIG. 47 shows a converging position when the fxcex8 lens is used as the converging lens 7. With the fxcex8 lens, it is possible to obtain an image height (operational distance) xcfx89 proportional to an incidence angle xcex8 of the laser beam L having passed through the focus position into the fxcex8 lens. It has been known that the following equation is established in this case:
xcfx89=fxc2x7xcex8
wherein f indicates a focal length of the fxcex8 lens and xcex8 indicates an incidence angle of the laser beam.
The converging lens 7 gets aberration like in a general optical glass lens, so that it is difficult to maintain the relation of xcfx89=fxc2x7xcex8. Therefore, in many cases a deviation between the theoretical value and the actual value is measured and this deviation is used as means for correcting an instruction value for a deflection angle of each of the Y-axial galvanoscanner 5 and X-axial galvanoscanner 6.
In this correction, correction of the converging lens is made for each machining position (x, y) to decide instruction values (xxe2x80x2, yxe2x80x2) for the deflecting devices (Y-axial galvanoscanner 5, X-axial galvanoscanner 6). This correction is often made by using an expression for conversion using a matrix, and to decide this expression for conversion, it is possible to cancel such an effect as aberration of a lens at the point of time by updating the expression for conversion used for correction independently from an ordinary machining sequence.
FIG. 48 is a flow chart showing a sequence for correcting and updating the parameters of the converging lens. To correct the aberration of the converging lens, drilling for correction is executed according to an instruction for machining positions having the configuration shown in FIG. 49 and the latticetype pattern shown as shown in FIG. 50 (step S611). However, because of aberration of the converging lens 7, in most cases the actually machined positions are displaced from the actually instructed lattice points as shown in FIG. 51.
When the drilling for correction is complete, a position of a machined hole is monitored with the vision sensor 9, and the coordinates of the machined hole are detected (step S612). With such operations a deviation between theoretical positions of the holes and an actually position of the machined holes can be obtained, so that coordinate transformation can be executed to obtain a desired machining position according to the obtained deviation. The coordinate transformation is often executed by an expression for conversion using a matrix, and fitting by means of, for instance, the least square method is executed according to deviation between a machining position theoretically obtained from characteristics of the converging lens 7 and an actual machined position, and then elements of a matrix [M] are obtained by means of correction matrix computing (step S613).
The converging lens 7 is required to have a high transmittance (or a low reflective index) against a wavelength of a laser beam, and especially in a case of a carbon oxide gas laser often used, there are some restrictions for a material of a lens, and generally a semiconductor crystalline material such as germanium (Ge) is used. It has been known that the lens material as described above has a very large temperature coefficient dn/dT for a refractive index n deciding the optical characteristics, and that germanium (Ge) has a temperature dependency dn/dT of 277 (/xc2x0 C.).
As the conventional type of laser machining device has the configuration as described above, when the temperature of the converging lens 7 changes due to effect by the ambient temperature or heat generation by the laser machining device itself, displacement of a machining position substantially proportional to the temperature change is disadvantageously generated, and due to which a machining position is displaced by 10 to 15 xcexcm per 1xc2x0 C., which disadvantageously causes a machining fault.
Displacement of a machining position caused by aberration of the converging lens 7 can be compensated by correction for aberration of a converging lens by means of the coordinate transformation described above, but when the temperature of the converging lens 7 changes during correction for aberration, optical characteristics of the converging lens 7 changes, and when temperature rises further, the lattice points actually machined generally disadvantageously shrink as shown in FIG. 52.
Further, a change in the temperature of the converging lens 7 not only displaces the machining position, but also changes the focal length of the lens and separates the focal point from a surface of a work which in turn generates a machining position fault.
As shown in FIG. 53, when temperature of the converging lens 7 is T, a laser bean coming into the converging lens 7 converges like a laser beam La with a focal point Pa positioned on a surface of the work, so that excellent machining can be carried out, but when temperature of the converging lens 7 changes by xcex4T, a laser beam having the same incidence angle converges like a laser beam Lb, so that displacement of a machining position by xcex4X is generated, and in addition a height of the focal point Pb goes higher by xcex4f.
This displacement of a machining position can be recognized only when the precision is checked after machining, so that sometimes a large number of works are continuously machined without knowing that there has generated a positional displacement and a large number of badly machined boards are disadvantageously produced.
Although displacement of a machining position can be corrected by frequently correcting aberration of a converging 5 lens, but to correct the aberration of a converging lens during operation in an automatic mode the operation is requires to be stopped which lowers the productivity.
There is no means for automatically detecting displacement of the focal length, so that it is required for an operator to previously obtain the focal length by actually operating the machining device, and in a case where the displacement of a focal length occurs as time goes by, there is no method to take appropriate countermeasures for the displacement of a focal length.
In the production of the printed boards, needs for further size reduction and higher machining precision in drilling have been becoming increasingly stronger in association with reduction of size and weight of electronic circuits and the trend for a higher degree of integration, so that there are strong needs for improving performance of a laser machining device.
The present invention was made to solve the problems as described above, and it is an object of the present invention to provide a laser machining device in which a converging performance of a converging lens does not depend on temperature change in the converging lens, and also which insures high precision machined and stable laser machining even when used continuously for a long time.
The present invention can provide a laser machining apparatus comprising a deflector for changing a direction of a laser beam outputted from a laser oscillator, and a converging lens for refracting a laser beam introduced from the deflector and focusing the laser beam onto a work to be machined, in which the converging lens comprises a plurality of lenses and has a lens position adjusting unit for changing a relative position between the plurality of lenses to cancel a change in the reflective index of the lenses because of a change in the temperature so that the converging characteristics of the converging lens does not depend on a change in the temperature of the converging lens.
Because of this configuration, a change in the converging characteristics due to a change in the reflective index of a lens due to a change of temperature is canceled, the converging characteristics of the converging lens does not depend on a change in the temperature of the converging lens, and a change of a machining position or the like due to a change in the temperature of ambient air or generation of heat in the laser machining apparatus itself does not occur, so that stable laser machining is executed.
The present invention can provide a laser machining apparatus in which the lens position adjusting unit comprises a temperature measuring unit for detecting the temperature of the converging lens, an actuator for driving a lens in a direction of the optic axis, and a control circuit for controlling the actuator to compensate the displacement of the focal point of the converging lens because of a change in the temperature of the converging lens detected by the temperature measuring unit.
Because of this configuration, the lens is displaced along the direction of the optic axis by the actuator so that displacement of a focal point because of a change in the temperature of the converging lens is compensated according to the temperature of the converging lens detected by the temperature measuring unit, dependency of the converging characteristics of the converging lens on a change in temperature of the converging lens is prevented, and a change of a machining position due to the temperature of the ambient air or generation of heat in the laser machining apparatus itself does not occur, so that stable laser machining is executed.
The present invention can provide a laser machining apparatus, in which the actuator comprises a feed screw mechanism for moving the lenses along the direction of the optic axis, and a motor for rotating and driving the feed screw mechanism.
Because of this configuration, the lens can be moved accurately by the feed screw mechanism along the direction of the optic axis.
The present invention can provide a laser machining apparatus, in which the actuator comprises a piezoelectric element.
Because of this configuration, the lens can be moved accurately by the piezoelectric element along the direction of the optic axis.
The present invention can provide a laser machining apparatus, in which the lens adjusting unit comprises a holding member made from a material with temperature dependency for holding the lenses and changes a position of the lenses by contraction or expansion of the holding member itself according to a change in the temperature.
Because of this configuration, the lenses are displaced along the direction of the optic axis according to the contraction or expansion of the holding member itself due to a change in temperature, displacement of a focal point because of a change in the temperature of the converging lens is compensated by this displacement, and dependency of the converging characteristics of the converging lens on a change in the temperature of the converging lens is prevented, so that a change of a machining position or the like due to a change in the temperature of ambient air or generation of heat in the laser machining apparatus itself does not occur, and hence stable laser machining high precision is executed.
The present invention can provide a laser machining apparatus comprising a deflector for changing the direction of a laser beam outputted from a laser oscillator, and a converging lens for refracting a laser beam introduced from the deflector and focusing the refracted laser beam onto a work to be machined, in which the converging lens has, in addition to a group of convex lenses for converging a light beam, a concave lens for temperature compensation incorporated therein, a change in the reflective index of the group of convex lenses due to a change in the temperature is canceled by a change in the reflective index of the concave lens, and the converging characteristics of the converging lens does not depend on a change in the reflective index of the converging lens because of a change in the temperature.
Because of this configuration, a change in the reflective index of the convex lens group is canceled due to a change in temperature of the concave lens, and dependency of the converging characteristics of the converging lens on a change in temperature of the converging lens is prevented, so that a specific control system is not required, a change of a machining position or the like due to a change in the temperature of ambient air or generation of heat in the laser machining apparatus itself does not occur, and hence stable laser machining with high precision is executed.
The present invention can provide a laser machining apparatus, in which the convex lens group of the converging lens is made of zinc selenite and the concave lens is made of germanium.
Because of this configuration, a change in reflective index of the convex lens group can accurately be canceled due to a change in temperature of the concave lens, and dependency of the converging characteristics of the converging lens on a change in temperature of the converging lens is prevented, so that a change of a machining position or the like due to a change in the temperature of ambient air or generation of heat in the laser machining apparatus itself does not occur, and hence stable laser machining with high precision is executed.
The present invention can provide a laser machining apparatus comprising a deflector for changing a direction of a laser beam outputted from a laser oscillator, and a converging lens for refracting a laser beam introduced from the deflector and focusing the refracted laser beam onto a work to be machined; the machining device further comprising a temperature measuring unit for detecting the temperature of the converging lens, and a temperature display unit for displaying temperature of the converging lens detected by the temperature measuring unit.
Because of this configuration, temperature of the converging lens detected by the temperature measuring unit is clearly displayed on the temperature display unit for the operator.
The present invention can provide a laser machining apparatus, in which the temperature display unit has a reset button and a temperature change is displayed according to temperature of the converging lens when the reset button is operated.
Because of this configuration, a change in the temperature of the converging lens when the reset button is operated is displayed on the temperature display unit and a temperature change when the reset button of the converging lens can be clearly seen by the operator.
The present invention can provide a laser machining apparatus comprising a deflector for changing a direction of a laser beam outputted from a laser oscillator, and a converging lens for refracting a laser beam introduced from the deflector and focusing the refracted laser beam onto a work to be machined; the laser machining apparatus further comprising a temperature measuring unit for detecting the temperature of the converging lens, and an alarming unit for generating an alarm when a change in the temperature of the converging lens exceeds a previously decided permissible value.
Because of this configuration, when a change in the temperature of the converging lens exceeds a permissible value, the alarming unit generates an alarm to alert the operator indicating that a change in the temperature of the converging lens has exceeded a prespecified permissible value.
The present invention can provide a laser machining apparatus comprising a deflector for changing a direction of a laser beam outputted from a laser oscillator, and a converging lens for refracting a laser beam introduced from the deflector and focusing the refracted laser beam onto a work to be machined, the laser machining apparatus further comprising a temperature a measuring unit for detecting the temperature of the converging lens, and a heating unit for heating the converging lens so that the temperature of the converging lens detected by the temperature measuring unit will be maintained at a specified constant value.
Because of this configuration, temperature of the converging lens is maintained at a specified constant value because of heating by the heating unit, and generation of a change in the converging characteristics of the converging lens due to a temperature change is prevented, so that a change of a machining position or the like due to a change in the temperature of the ambient air or generation of heat in the laser machining apparatus itself does not occur, and hence stable laser machining with high precision is executed.
The present invention can provide a laser machining apparatus comprising a deflector for changing the direction of the laser beam outputted from a laser oscillator, and a converging lens for refracting the laser beam introduced from the deflector and focusing the refracted laser beam onto a work to be machined, the laser machining apparatus further comprising a temperature measuring unit for detecting the temperature of the converging lens, and a temperature control unit for cooling the converging lens so that the temperature of the converging lens detected by the temperature measuring unit will be maintained at a specified constant value.
Because of this configuration, temperature of the converging lens is maintained at a specified constant value because the converging lens is cooled by the temperature control unit, and generation of a change in the converging characteristics of the converging lens due to a change in the temperature is prevented, so that a change in the machining position or the like due to a change in the temperature of the ambient air or generation of heat in the laser machining apparatus itself does not occur, and hence stable laser machining with high precision is executed.
The present invention can provide a laser machining apparatus, in which the temperature control unit is a Peltier element.
Because of this configuration, the converging lens is cooled by the Peltier element and the temperature of the converging lens is maintained at a specified constant value, and generation of a change in the converging characteristics of the converging lens is prevented, so that a change in the machining position or the like due to a change in the temperature of the ambient temperature or generation of heat in the laser machining apparatus itself does not occur, and hence stable laser machining with high precision is executed.
The present invention can provide a laser machining apparatus comprising a deflector for changing the direction of a laser beam outputted from the laser oscillator, and a converging lens for refracting the laser beam introduced from the deflector and focusing the refracted laser beam onto a work to be machined; the laser machining apparatus further comprising an heat-insulating unit for protecting the converting lens from the temperature of ambient air.
Because of this configuration, heat from the ambient air is not conducted to the converging lens because of the presence of the heat-insulating unit and possibility of generation of a change in the optical characteristics of the converging lens due to a change in the temperature is suppressed, so that a change in the machining position due to a change in the temperature of the ambient air is prevented, and hence stable laser machining with high precision is executed.
The present invention can provide a laser machining apparatus, in which the heat-insulating unit comprises an outer cylindrical body surrounding the converging lens, a heat insulating material filled in a heat-insulating space defined by the converging lens and the outer cylindrical body surrounding the converging lens, and a window seal plate through which a laser beam can be passed through and also which is so located that an upper edge and a lower edge of the heat-insulating space is sealed.
Because of this configuration, conduction of heat from the ambient air to the converging lens is prevented because of the presence of heat-insulating material generation of a change in the converging characteristics of the converging lens due to a change in the temperature is suppressed, so that a change in the machining position due to a change in the temperature of the ambient air is prevented, and hence stable laser machining with high precision is executed.
The present invention can provide a laser machining apparatus, in which the heat-insulating unit supports the lenses constituting a converging lens via a heat-insulating member made from a heat-insulating substance.
Because of this configuration, conduction of heat from the ambient air to the converging lens is prevented because of the presence of the heat-insulating member, and generation of a change in the converting characteristics of the converging lens due to a change in the temperature is prevented, so that table laser machining with high precision is executed.
The present invention can provide a laser machining apparatus, in which the heat-insulating unit has a plurality of projections and also has a lens mount member for contacting the tips of the projections to the lenses constituting the converging lens points to points to hold the lenses.
Because of this configuration, because the lenses are supported by means of point contact heat conduction between the lens holder and lens is substantially eliminated, generation of a change in the converging characteristics of the converging lens due to a change in the temperature is suppressed, and heat conduction from ambient air to the lens is suppressed, so that a change in the machining position due to a change in the temperature of the ambient air is prevented, and hence stable laser machining with high precision is executed.
The present invention can provide a laser machining apparatus, in which the heat-insulating unit has a lens mount member having continuous projections and the tips of these continuous projections contact the lenses constituting the converging lens line to line to hold the lenses.
Because of this configuration, because the lenses are supported by means of line contact heat conduction between the lens holders and lenses is substantially eliminated, generation of a change in the converging characteristics of the converging lens due to a change in the temperature is suppressed, and heat conduction from the ambient air to the lens is suppressed, so that a change in the machining position due to a change in the temperature of the ambient air is prevented, and hence stable laser machining with high precision is executed.
The present invention can provide a laser machining apparatus, in which the converging lens comprises a plurality of convex lenses, topmost and bottommost convex lenses thereof are made from a lens material having optical characteristics not depending on temperature, and the other convex lenses located in the intermediate section are made from a lens material having optical characteristics depending on temperature.
Because of this configuration, the topmost and bottommost convex lenses function as heat barriers, and as for the convex lenses located in the intermediate section each made from a material having optical characteristics depending on temperature, heat conduction thereto from the ambient air is prevented, and generation of a change in the converging characteristics of the converging lens due to a change in the temperature is suppressed, and heat conduction from the ambient air to the lens is suppressed, so that a change in the machining position due to a change in the temperature of the ambient air is prevented, and hence stable laser machining with high precision is executed.
The present invention can provide a laser machining apparatus, in which the convex lenses provided in the intermediate section are held by a lens mount member having a projection and contacting the tips of the projection to a lens constituting the converging lens line to line.
Because of this configuration, heat conduction from the lens holder to the convex lenses located in the intermediate section is suppressed, and generation of a change in the converging characteristics of the lens due to a change in the temperature is suppressed, so that a change in the machining position due to a change in the temperature of the ambient air is prevented, and hence stable laser machining with high precision is executed.
The present invention can provide a laser machining apparatus comprising a deflector for changing the direction of a laser beam outputted from a laser oscillator, and a converging lens for refracting the laser beam introduced from the deflector and focusing the laser beam onto a work to be machined, the laser machining apparatus further comprising a temperature measuring unit for detecting the temperature of the converging lens, and a temperature adjusting unit for adjusting the temperature of the ambient air in a section where the converging lens is provided so that temperature of the converging lens detected by the temperature measuring unit is maintained at a specified contact value.
Because of this feature, temperature of the converging lens is maintained at a specified constant value, and generation of a change in the converging characteristics of the lens due to a change in the temperature is suppressed, so that a change in the machining position due to a change in the temperature of the ambient air is prevented, and hence stable laser machining with high precision is executed.
The present invention can provide a laser machining apparatus comprising a deflector for changing the direction of a laser beam outputted from a laser oscillator, and a converging lens for refracting the laser beam introduced from the deflector and focusing the laser beam onto a work to be machined, the laser machining apparatus further comprising a cancel mechanism for canceling a change in the optical characteristics of the converging lens due to a change in the temperature of the converging lens by adjusting an angle of a laser beam introduced into the converging lens.
Because of this configuration, an angle of a laser beam introduced into the converging lens is adjusted by the cancel mechanism, the a change in the optical characteristics of the converging lens due to a change in the temperature of the converging lens is canceled by means of this angle adjustment, so that a change in the machining position or the like due to a change in the temperature of ambient air or generation of heat in the laser machining apparatus itself is not generated, and hence stable laser machining with high precision is executed.
The present invention can provide a laser machining apparatus, in which the cancel mechanism is a deflection amount instruction correcting unit for correcting an instruction value for the amount of deflection by the deflector.
Because of this configuration, an instruction value for the amount of deflection by the deflector is corrected by the deflection amount instruction correcting unit, an angle of a laser beam introduced into the converging lens is adjusted by means of this correction, and a change in the optical characteristics of the converging lens due to a change in the temperature of the converging lens is canceled through this angle adjustment, so that a change in the machining position or the like due to a change in the temperature of the ambient air or generation of heat in the laser machining apparatus itself is not generated, and hence stable laser machining with high precision is executed.
The present invention can provide a laser machining apparatus comprising a temperature measuring unit for detecting the temperature of the converging lens, in which the deflection amount instruction correcting unit corrects an instruction value for the amount of deflection by the deflector based on a correction parameter set according to temperature of the converging lens detected by the temperature measuring unit.
Because of this configuration, the deflection amount instruction correcting unit corrects an instruction value for the amount of deflection by the deflector based on the correction parameter set according to temperature of the converging lens detected by the temperature measuring unit, an angle of a laser beam introduced into the converging lens is adjusted through this correction, and also a change in the optical characteristics of the converging lens due to a change in the temperature of the converging lens is canceled by means of this angle adjustment, so that a change in the machining position or the like due to a change in the temperature of the ambient air or generation of heat in the laser machining apparatus itself is not generated and stable laser machining with high precision is executed.
The present invention can provide a laser machining apparatus, in which the deflection amount instruction correcting unit executes correction of an instruction for the amount of deflection by means of coordinate transformation by obtaining a coordinate transformation function from the machining position error in fixed point machining.
Because of this configuration, an instruction value for the amount of deflection by the deflector is corrected by the deflection amount instruction correcting unit by means of coordinate transformation by obtaining a coordinate transformation function according to a machining position error in fixed point machining, angle of the laser beam introduced into the converging lens is adjusted through this correction, and a change in the optical characteristics of the converging lens due to a change in the temperature of the converging lens is canceled by means of this angle adjustment, so that a change in the machining position or the like due to a change in the temperature of the ambient air or generation of heat in the laser machining apparatus itself is not generated, and hence stable laser machining with high precision is executed.
The present invention can provide a laser machining apparatus, in which the deflection amount instruction correcting unit executes correction of an instruction for the amount of deflection with a correction matrix obtained from a machining position error in fixed point machining.
Because of this configuration, an instruction value for the amount of deflection by the deflector is corrected by the deflection amount instruction correcting unit by means of coordinate transformation by obtaining a correction matrix according to a machining position error in fixed point machining, angle of the laser beam introduced into the converging lens is adjusted through this correction, and a change in the optical characteristics of the converging lens due to a change in the temperature of the converging lens is canceled, so that a change in the machining position or the error due to a change in the temperature of the ambient air or generation of heat in the laser machining apparatus itself is not generated, non-linear positional displacement can completely be corrected, and hence laser machining with high precision can be executed.
The present invention can provide a laser machining apparatus, in which the coordinate trans formation function or correction matrix is updated before start of laser machining each time laser machining is executed.
Because of this configuration, each time laser machining is executed, a coordinate transformation function or a correction matrix is updated before start of laser machining, and a change in the optical characteristics of the converging lens due to a change in the temperature of the converging lens is canceled by correcting an instruction for the amount of deflection by the deflector with an updated coordinate transformation function or a correction matrix, so that a change of a machining position or the error due to a change in the temperature of the ambient air or generation of heat in the laser machining apparatus itself is not generated, and hence laser machining with high precision can be executed.
The present invention can provide a laser machining apparatus comprising a temperature measuring unit for detecting temperature of the converging lens, in which the coordinate transformation function or correction matrix is updated, when a change in the temperature of the converging lens detected by the temperature measuring unit exceeds a specified value, before start of laser machining according to temperature of the converging lens at the point of time.
Because of this configuration, when a change in the temperature of the converging lens detected by the temperature measuring device exceeds a specified value, a coordinate transformation function or a correction matrix is changed, and a change in the optical characteristics of the converging lens due to a change in the temperature of the converting lens is canceled by correcting an instruction for the amount of deflection by the deflector with the updated coordinate transformation function or correction matrix, so that a change in the machining position or the error due to a change in the temperature of the ambient air or generation of heat in the laser machining apparatus itself is not generated, and hence laser machining with high precision can be executed.
The present invention can provide a laser machining apparatus, in which the coordinate transformation function of correction matrix is updated at prespecified timing.
Because of this configuration, a coordinate transformation function or a correction matrix is updated at a specified timing, and a change in the optical characteristics of the converging lens due to a change in the temperature of the converging lens is canceled by correcting an instruction for the amount of deflection by the deflector with the updated coordinate transformation function or correction matrix, so that a change in the machining position or the error due to a change in the temperature of the ambient air or generation of heat in the laser machining apparatus itself is not generated, and hence laser machining with high precision can be executed.
The present invention can provide a laser machining apparatus, in which the coordinate transformation function or correction matrix is updated each time a specified period of time has passed.
Because of this configuration, each time a specified period of time has passed, periodically a coordinate transformation function or a correction matrix is updated, and a change in the optical characteristics of the converging lens due to a change in the temperature of the converging lens is canceled by correcting an instruction for the amount of deflection by the deflector with the updated coordinate transformation function or correction matrix, so that a change in the machining position or the error due to a change in the temperature of the ambient air or generation of heat in the laser machining apparatus itself is not generated, and hence laser machining with high precision can be executed.
The present invention can provide a laser machining apparatus comprising a temperature measuring unit for detecting the temperature of the converging lens by previously obtaining a correction matrix for temperature of each converging lens, in which a correction matrix corresponding to the temperature of the converging lens detected by the temperature measuring unit is used.
Because of this configuration, a change in the optical characteristics of the converging lens due to a change in the temperature of the converging lens by correcting an instruction for the amount of deflection by the deflector with a correction matrix based on a previously obtained temperature of each converging lens and without requiring execution of the processing for updating the correction matrix each time laser machining is executed, so that a change in the machining position or the error due to a change in the temperature of the ambient air or generation of heat in the laser machining apparatus itself is not generated, and hence laser machining with high precision can be executed.
The present invention can provide a laser machining apparatus, in which the cancel mechanism includes a variable gain setting unit for variably setting a gain of an instruction value for the amount of deflection by the deflector according to temperature of the converging lens detected by the temperature measuring unit.
Because of this configuration, an instruction for the amount of deflection is executed by means of gain adjustment for a deflection instruction value with the variable gain setting unit, and a change in the optical characteristics of the converging lens due to a change in the temperature of the converging lens is canceled through this, correction, so that a change in the machining position or the error due to a change a in the temperature of the ambient air or generation of heat in the laser machining apparatus itself is not generated, and hence laser machining with high precision can be executed.
The present invention can provide a laser machining apparatus, in which the cancel mechanism includes a bend mirror for adjusting an angle of a laser beam introduced into the deflector.
Because of this configuration, an angle of a laser beam introduced into the deflector is adjusted by the bend mirror, and a change in the optical characteristics of the converging lens due to a change in the temperature of the converging lens is canceled through this adjustment, so that a change in the machining position or the error due to a change in the temperature of the ambient air or generation of heat in the laser machining apparatus itself is not generated, and hence laser machining with high precision can be executed.
The present invention can provide a laser machining apparatus comprising a deflector for changing a direction of a laser beam outputted from a laser oscillator, and a converging lens for refracting a laser beam introduced from the deflector and focusing the laser beam onto a work to be machined, the laser machining apparatus further comprising a temperature measuring unit for detecting the temperature of the converging lens, and a machining table driving instruction correcting unit for correcting a positional instruction for a work to be machined under the converging lens according to temperature of the converging lens detected by the temperature measuring unit and also for canceling fluctuation of the optical characteristics of the converging lens due to fluctuation in temperature of the converging lens.
Because of this configuration, the machining table driving instruction correcting unit corrects an instruction for the position of the work to be machined according to temperature of the converging lens, and a change of a machining position due to a change in the optical characteristics of the converging lens due to a change in the temperature of the converging lens is canceled through this positional correction, so that a change in the machining position or the error due to a change in the temperature of the ambient air or generation of heat in the laser machining apparatus itself is not generated, and hence laser machining with high precision can be executed.
The present invention can provide a laser machining apparatus comprising a deflector for changing a direction of a laser beam outputted from a laser oscillator, and a converging lens for refracting a laser beam introduced from the deflector and focusing the laser beam onto a work to be machined, the laser machining apparatus further comprising a temperature measuring unit for detecting the temperature of the converging lens, and a variable wavelength laser oscillator for variably setting a wavelength of an outputted laser beam according to the temperature of the converging lens detected by the temperature measuring unit so that a change in the optical characteristics of the converging lens due to a change in the temperature of the converging lens is canceled.
Because of this configuration, a wavelength of a laser beam can be set so that positional displacement caused by a change in the optical characteristics of the converging lens due to a change in the temperature of the converging lens is canceled, so that stable and high precision laser machining can be executed without being affected by a change in the temperature of the converging lens.
The present invention can provide a laser machining apparatus comprising a deflector for changing the direction of a laser beam outputted from a laser oscillator, and a converging lens for refracting the laser beam introduced from the deflector and focusing the laser beam onto a work to be machined, the laser machining apparatus further comprising a temperature measuring unit for detecting the temperature of the converging lens, and a cancel mechanism for adjusting a distance between the converging lens and the deflector according to the temperature of the converging lens detected by the temperature measuring unit to cancel a change in the optical characteristics of the converging lens due to a change in the temperature of the converging lens.
Because of this configuration, a distance between the converging lens and deflector is adjusted by the cancel mechanism according to the temperature of the converging lens, and a change in the optical characteristics of the converging lens due to a change in the temperature of the converging lens is canceled through this adjustment, so that a change in the machining position due to change in the temperature of the ambient air or generation of heat in the laser machining apparatus itself is prevented, and hence laser machining with high precision is executed.
The present invention can provide a laser machining apparatus comprising a deflector for changing the direction of a laser beam outputted from a laser oscillator, and a converging lens for refracting the laser beam introduced from the deflector and focusing the laser beam onto a work to be machined, the laser machining apparatus further comprising a temperature measuring unit for detecting the temperature of the converging lens, and an adaptive optics for adjusting a divergence angle of a laser beam according to the temperature of the converging lens detected by the temperature measuring unit so that a change in the focal length of the converging lens due to a change in the temperature of the converging lens is canceled.
Because of this configuration, a divergence angle of the laser beam is adjusted by the adaptive optics according to the temperature of the converging lens, and a position of a focal point can be maintained on the surface of the work through this adjustment, so that stable and high precision laser machining can be executed even if temperature of the converging lens changes.
The present invention can provide a laser machining apparatus comprising a deflector for changing the direction of a laser beam outputted from a laser oscillator, and a converging lens for refracting the laser beam introduced from the deflector and focusing the laser beam onto a work to be machined, the laser machining apparatus further comprising a temperature measuring unit for detecting the temperature of the converging lens, and a collimate lens position adjusting mechanism for adjusting a position of a collimate lens according to the temperature of the converging lens detected by the temperature measuring, unit so that a change in the focal length of the converging lens due to a change in the temperature of the converging lens is canceled.
Because of this configuration, a position of the collimate lens is adjusted by the collimate lens position adjusting mechanism, and a position of a focal point can be maintained on the surface of the work by adjusting a divergence angle of the laser beam according to a change in the focal length due to a change in the temperature of the converging lens through this adjustment, so that stable and high precision laser machining can be executed even if temperature of the converging lens changes.
The present invention can provide a laser machining apparatus comprising a deflector for changing the direction of a laser beam outputted from a laser oscillator, and a converging lens for refracting the laser beam introduced from the deflector and focusing the laser beam onto a work to be machined, the laser machining apparatus further comprising a temperature measuring unit for detecting the temperature of the converging lens, and a machining table height adjusting mechanism for adjusting the distance between the converging lens and the work to be machined so that a change in the focal length of the converging lens due to a change in temperature of the converging lens.
Because of this configuration, a distance between the converging lens and a work to be machined is adjusted by the machining table height adjusting mechanism, and a position of a focal point can be maintained on the surface of the work through this adjustment, so that stable and high precision laser machining can be executed even if temperature of the converging lens changes.